Optical Transceiver, Optical Communication System, Optical Transmission Device, Method for Setting Optical Transceiver, and Program

Abstract

The present invention repeatedly transmits an optical signal (S1) for channel setting from a variable-wavelength optical transmission unit (10) while changing channels in accordance with a first command signal (INS) until a variable-wavelength optical reception unit (20) receives an optical signal (S2) for channel setting. When the variable-wavelength optical reception unit (20) has received the optical signal (S2) for channel setting, the channel indicated by corresponding channel information is set as a channel for the optical signal received by the variable-wavelength optical reception unit (20). When a second command signal (INS_M) is received after reception of the first command signal (INS), the channel for the optical signal transmitted by the variable-wavelength optical transmission unit (10) is set to a first designated channel, and the channel for the optical signal received by the variable-wavelength optical reception unit (20) is set to a second designated channel.

Description

Technical Field

[0001] The present invention relates to an optical transceiver, an optical communication system, an optical transmission device, a method for setting an optical transceiver, and a computer-readable medium.

Background Art

[0002] An optical communication system that enables optical communication by connecting terrestrial base stations via an optical cable is widely used. Each base station is provided with an optical transmission device equipped with one or more optical transceivers. When starting to use an optical transceiver, initial settings of the optical transceiver are performed.

[0003] A technique has been disclosed in which the transmission speed, data format, and transmission format are adjusted between optical transceivers before starting data communication (Patent Document 1). In this technique, test signals for setting the transmission speed and transmission format between optical transceivers are transmitted and received between the optical transceivers. The transmission speed is set by comparing the transmission speed used for transmitting the test signal with the transmission speed of the received test signal. The transmission format is set corresponding to the estimated transmission line state according to the error detection of the test signal. The data format is determined by transmitting and receiving information regarding the data format after the transmission speed and transmission format are determined. After these are determined, communication between the optical transceivers is started.

[0004] In addition, a method for starting two-way communication of data packets between optical transceivers in an uncommunicated state has been proposed (Patent Document 2). In this method, prior to the two-way communication of data packets, connection packets having specific information of each optical transceiver and having a low speed equal to or lower than the transmission speed of the data packets are transmitted and received between the optical transceivers via an optical fiber transmission line. Then, according to the specific information of the connection packet received by each optical transceiver, one of the optical transceivers is set as a master and the other as a slave, and the transmission method set by the master optical transceiver is notified to the slave optical transceiver by a setting packet. Two-way communication between the optical transceivers is performed by the transmission method set by this notification.

[0005] Furthermore, in a PON (Passive Optical Network) system composed of an OLT (Optical Line Terminal) and an ONU (Optical Network Unit), a method for performing wavelength negotiation for communication between optical modules has been proposed (Patent Document 3). In this method, an optical module (referred to as a first optical module) periodically transmits a wavelength idle signal of a selected first wavelength to a counterpart optical module (referred to as a second optical module). This wavelength idle signal indicates that the selected first wavelength is available, and the second optical module that has received the wavelength idle signal transmits a wavelength request message of a second wavelength corresponding to the first wavelength to the first optical module. If the first optical module receives the wavelength request message, it transmits a wavelength permission message to the second optical module in order to permit the use of the selected wavelength. Thereby, the wavelength used for the transmission and reception of optical signals between the two optical modules is determined.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] In an optical transmission device, generally, a plurality of optical transceivers are mounted, and it is necessary to perform an initial setting for setting a channel (wavelength) used for transmission and reception by each optical transceiver. In this case, if the channel settings of a large number of optical transceivers mounted on the optical transmission device are performed manually, it will take a great deal of time for the setting work. Therefore, from the viewpoint of shortening the working time, it is desirable that when an optical transceiver is mounted on an optical transmission device, the channel of the optical signal transmitted and received by the optical transceiver can be autonomously set as an initial setting.

[0008] In the method of Patent Document 3, although the channel (wavelength) used for transmission and reception can be set by performing wavelength negotiation between two optical modules (optical transceivers), it is premised that the transmission and reception of an optical signal of a specific channel can be performed between the two optical modules in the first place. In other words, the first and second wavelengths used must be assigned manually. That is, the method of Patent Document 3 only confirms that the transmission and reception path can be used using the assigned channel, and cannot autonomously set the channel to be used.

[0009] The present invention has been made in view of the above circumstances, and an object thereof is to autonomously set the channel of the optical signal transmitted and received by the optical transceiver.

Means for Solving the Problems

[0010] An optical transceiver according to an aspect of the present invention includes a wavelength-variable optical transmitter configured to be able to transmit a first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal by superimposing the first channel setting optical signal on a first main signal obtained by modulating transmission target data; a wavelength-variable optical receiver configured to transfer second channel information indicating a channel of the second channel setting optical signal included in the second channel setting optical signal when receiving the second channel setting optical signal superimposed on a second main signal obtained by modulating reception target data from another optical transceiver; and a control unit configured to control the wavelength-variable optical transmitter and the wavelength-variable optical receiver. When receiving a first command signal, the control unit repeatedly causes the wavelength-variable optical transmitter to transmit the first channel setting optical signal while changing a transmission channel of the first channel setting optical signal until the wavelength-variable optical receiver receives the second channel setting optical signal. When the wavelength-variable optical receiver receives the second channel setting optical signal, the control unit sets the channel indicated by the second channel information as a channel of an optical signal received by the wavelength-variable optical receiver. When receiving a second command signal for designating a first designated channel of an optical signal transmitted by the wavelength-variable optical transmitter and a second designated channel of an optical signal received by the wavelength-variable optical receiver after receiving the first command signal, the control unit sets the channel of the optical signal transmitted by the wavelength-variable optical transmitter to the first designated channel and sets the channel of the optical signal received by the wavelength-variable optical receiver to the second designated channel.

[0011] An optical communication system according to one aspect of the present invention includes a plurality of optical transceivers, a first optical multiplexer / demultiplexer that multiplexes and outputs optical signals output from the plurality of optical transceivers and demultiplexes received optical signals to the plurality of optical transceivers according to channels, two opposing optical transmission devices having the first optical multiplexer / demultiplexer, and an optical cable that connects between the two opposing optical transmission devices. A first optical transceiver, which is an optical transceiver of one of the optical transmission devices, includes a wavelength-variable optical transmission unit configured to be able to transmit a first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal by superimposing it on a first main signal obtained by modulating transmission target data. When receiving a second channel setting optical signal superimposed on a second main signal obtained by modulating reception target data from a second optical transceiver, which is an optical transceiver of the other optical transmission device, the first optical transceiver includes a wavelength-variable optical reception unit configured to transfer second channel information indicating a channel of the second channel setting optical signal included in the second channel setting optical signal, and a control unit configured to control the wavelength-variable optical transmission unit and the wavelength-variable optical reception unit. When receiving a first command signal, the control unit repeatedly causes the wavelength-variable optical transmission unit to transmit the first channel setting optical signal while changing a transmission channel of the first channel setting optical signal until the wavelength-variable optical reception unit receives the second channel setting optical signal. When the wavelength-variable optical reception unit receives the second channel setting optical signal, the control unit sets a channel indicated by the second channel information as a channel of an optical signal received by the wavelength-variable optical reception unit. When receiving a second command signal that designates a first designated channel of an optical signal transmitted by the wavelength-variable optical transmission unit and a second designated channel of an optical signal received by the wavelength-variable optical reception unit after receiving the first command signal, the control unit sets the channel of the optical signal transmitted by the wavelength-variable optical transmission unit to the first designated channel and sets the channel of the optical signal received by the wavelength-variable optical reception unit to the second designated channel.

[0012] An optical transmission device according to one aspect of the present invention includes a plurality of optical transceivers, and a first optical multiplexer / demultiplexer that multiplexes and outputs optical signals output from the plurality of optical transceivers and demultiplexes the received optical signals to the plurality of optical transceivers according to channels. The optical transceiver includes a wavelength-variable optical transmission unit configured to be able to transmit a first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal by superimposing it on a first main signal obtained by modulating transmission target data, and a wavelength-variable optical reception unit that transfers second channel information indicating a channel of the second channel setting optical signal included in the second channel setting optical signal received when the second channel setting optical signal superimposed on a second main signal obtained by modulating reception target data is received from an optical transceiver of another optical transmission device connected via an optical cable, and a control unit that controls the wavelength-variable optical transmission unit and the wavelength-variable optical reception unit. When the control unit receives a first command signal, the control unit repeatedly causes the wavelength-variable optical transmission unit to transmit the first channel setting optical signal while changing a transmission channel of the first channel setting optical signal until the wavelength-variable optical reception unit receives the second channel setting optical signal. When the wavelength-variable optical reception unit receives the second channel setting optical signal, the control unit sets the channel indicated by the second channel information as a channel of an optical signal received by the wavelength-variable optical reception unit. When the control unit receives a second command signal that designates a first designated channel of an optical signal transmitted by the wavelength-variable optical transmission unit and a second designated channel of an optical signal received by the wavelength-variable optical reception unit after receiving the first command signal, the control unit sets the channel of the optical signal transmitted by the wavelength-variable optical transmission unit to the first designated channel and sets the channel of the optical signal received by the wavelength-variable optical reception unit to the second designated channel.

[0013] A method for setting an optical transceiver according to an aspect of the present invention is as follows. In an optical transceiver including a wavelength-variable optical transmitter configured to be able to transmit a first optical signal for channel setting including first channel information indicating a channel of the first optical signal for channel setting by superimposing it on a first main signal obtained by modulating transmission target data, a wavelength-variable optical receiver configured to transfer second channel information indicating a channel of the second optical signal for channel setting included in the second optical signal for channel setting when the second optical signal for channel setting superimposed on a second main signal obtained by modulating reception target data is received from another optical transceiver, and a control unit configured to control the wavelength-variable optical transmitter and the wavelength-variable optical receiver, when a first command signal is received, the wavelength-variable optical transmitter is caused to repeatedly transmit the first optical signal for channel setting while changing a transmission channel of the first optical signal for channel setting until the wavelength-variable optical receiver receives the second optical signal for channel setting; when the wavelength-variable optical receiver receives the second optical signal for channel setting, the channel indicated by the second channel information is set as a channel of an optical signal received by the wavelength-variable optical receiver; and when a second command signal for designating a first designated channel of an optical signal transmitted by the wavelength-variable optical transmitter and a second designated channel of an optical signal received by the wavelength-variable optical receiver is received after the first command signal is received, the channel of the optical signal transmitted by the wavelength-variable optical transmitter is set to the first designated channel, and the channel of the optical signal received by the wavelength-variable optical receiver is set to the second designated channel.

[0014] A non-transitory computer-readable medium storing a program according to an aspect of the present invention includes a wavelength-variable optical transmitter configured to be able to transmit the first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal by superimposing it on a first main signal obtained by modulating transmission target data, and when receiving a second channel setting optical signal superimposed on a second main signal obtained by modulating reception target data from another optical transceiver, a wavelength-variable optical receiver that transfers second channel information indicating a channel of the second channel setting optical signal included in the second channel setting optical signal, and a control unit having a computer that performs processing for controlling the wavelength-variable optical transmitter and the wavelength-variable optical receiver. In the optical transceiver, when receiving a first command signal, a process of repeatedly transmitting the first channel setting optical signal while changing a transmission channel of the first channel setting optical signal in the wavelength-variable optical transmitter until the wavelength-variable optical receiver receives the second channel setting optical signal, when the wavelength-variable optical receiver receives the second channel setting optical signal, a process of setting the channel indicated by the second channel information as a channel of an optical signal received by the wavelength-variable optical receiver, and when receiving a second command signal that designates a first designated channel of an optical signal transmitted by the wavelength-variable optical transmitter and a second designated channel of an optical signal received by the wavelength-variable optical receiver after receiving the first command signal, a process of setting the channel of the optical signal transmitted by the wavelength-variable optical transmitter to the first designated channel and setting the channel of the optical signal received by the wavelength-variable optical receiver to the second designated channel are performed by the computer.

Effect of the Invention

[0015] According to the present invention, the channels of the optical signals transmitted and received by the optical transceiver can be autonomously set.

Brief Description of the Drawings

[0016]

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Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the same reference numerals are assigned to the same elements, and redundant descriptions will be omitted as necessary.

[0018] Embodiment 1 The optical communication system 1000 according to Embodiment 1 will be described. FIG. 1 schematically shows the basic configuration of the optical communication system 1000 according to Embodiment 1. In the optical communication system 1000, optical transmission devices 1 and 2 are respectively provided at terrestrial end stations BS1 and BS2. The optical transmission devices 1 and 2 are connected by optical cables C1 and C2. The optical cables C1 and C2 may be laid on land or laid on the seabed. In this example, the optical cable C1 is used as a cable for transmitting the optical signal transmitted from the optical transmission device 1 to the optical transmission device 2. The optical cable C2 is used as a cable for transmitting the optical signal transmitted from the optical transmission device 2 to the optical transmission device 1. Note that one or more optical amplifiers AMP may be inserted into the optical cables C1 and C2 to compensate for the optical signal attenuated by transmission.

[0019] FIG. 1 shows a simplified configuration of the optical communication system for simplicity. For example, one optical transmission device may be communicably connected to two or more optical transmission devices by an optical cable. Further, an optical branching insertion device for performing ADD / DROP of an optical signal may be inserted into the optical cable as necessary to branch a branch path from a trunk path. However, this is merely an example, and it goes without saying that the optical communication system may have an arbitrary path (trunk path and branch path) that enables optical communication between an arbitrary number of optical transmission devices.

[0020] The configuration of the optical transmission device will be described. The optical transmission device includes a plurality of optical transceivers, an optical multiplexer that multiplexes the optical signals to be transmitted and outputs a multiplexed optical signal, and an optical demultiplexer that demultiplexes the received multiplexed optical signal to each optical transceiver. Hereinafter, for simplicity, the optical multiplexer and the optical demultiplexer are integrated and treated as one optical multiplexer / demultiplexer.

[0021] Fig. 2 schematically shows the configurations of the optical transmission devices 1 and 2 according to Embodiment 1 and an example of optical signal transmission and reception. The optical transmission device 1 includes a plurality of optical transceivers and an optical multiplexer / demultiplexer M1 (also referred to as a second optical multiplexer / demultiplexer). Here, an example is shown in which the optical transmission device 1 has 25 optical transceivers A1 to A25. Two different channels are assigned to each of the optical transceivers A1 to A25.

[0022] The ports of the optical multiplexer / demultiplexer M1 connected to the optical transceivers are provided in the number of channels. The transmission port of the optical transceiver Ai (i is an integer from 1 to 25) is connected to the port of channel CH(2i - 1) of the optical multiplexer / demultiplexer M1, and the reception port is connected to the port of channel CH(2i). In other words, the transmission channel CH(2i - 1) and the reception channel CH(2i) are assigned to the optical transceiver Ai. That is, channels CH1 and CH2, CH3 and CH4, CH5 and CH6, ···, CH49 and CH50 are assigned to the optical transceivers A1, A2, A3, ···, A25. In this way, specific channels are assigned to each of the two ports of the optical transceiver without overlapping within the optical transmission device.

[0023] The optical transmission device 2 has the same configuration as the optical transmission device 1. That is, the optical transmission device 2 includes 25 optical transceivers B1 to B25 and an optical multiplexer / demultiplexer M2 (also referred to as a first optical multiplexer / demultiplexer).

[0024] The ports of the optical multiplexer / demultiplexer M2 connected to the optical transceiver are provided in number equal to the number of channels. The receiving port of the optical transceiver Bi is connected to the port of channel CH(2i - 1) of the optical multiplexer / demultiplexer M2, and the transmitting port is connected to the port of channel CH(2i). In other words, for the optical transceiver Bi, the transmitting channel CH(2i) and the receiving channel CH(2i - 1) are allocated. That is, for the optical transceivers B1, B2, B3, ···, B25, channels CH1 and CH2, CH3 and CH4, CH5 and CH6, ···, CH49 and CH50 are allocated. In this way, a specific channel is allocated to each of the two ports of the optical transceiver without duplication within the optical transmission device.

[0025] With the above configuration, two common channels are allocated to the optical transceiver Ai and the optical transceiver Bi, and optical signal transmission and reception can be performed using these two channels.

[0026] In this example, focusing on the optical transceiver A2 of the optical transmission device 1 and the optical transceiver B2 of the optical transmission device 2, the optical signal transmission and reception paths are shown. The optical transceiver A2 transmits an optical signal using channel CH3, and the optical transceiver B2 receives the optical signal of the transmitted channel CH3. Also, the optical transceiver B2 transmits an optical signal using channel CH4, and the optical transceiver A2 receives the optical signal of the transmitted channel CH4.

[0027] Note that in Fig. 2, only the optical transceiver A2 and the optical transceiver B2 are focused on for simplicity of explanation. Needless to say, other optical transceivers can also perform optical signal transmission and reception using two channels in the same way.

[0028] In this way, to perform optical signal transmission and reception of a specific channel, it is necessary to set the channels used by the optical transceiver on the transmitting side and the optical transceiver on the receiving side. Generally, the operation of setting channels for the optical transceiver is performed as an initial setting operation when the optical transceiver is attached to the optical transmission device.

[0029] However, for example, when using up to 50 channels as in the above-described optical communication system, when using two optical transmission devices, it is necessary to perform setting operations for two channels, that is, 100 times of setting operations, for each of a total of 50 optical transceivers. However, if this setting operation is performed manually, there is a problem that the required working time becomes enormous. In addition, since it is also necessary to perform a large number of setting operations without mistakes, it can be considered that there is a problem from the viewpoint of reliability in the manual setting operation.

[0030] Therefore, in the present embodiment, in order to address such problems, an optical transceiver that autonomously performs channel setting processing when an optical transceiver is attached to an optical transmission device will be described.

[0031] For example, when optical transceivers A2 and B2 are attached to an optical transmission device, optical transceivers A2 and B2 autonomously execute channel setting processing. At this time, an optical signal for channel setting is transmitted and received between optical transceivers A2 and B2.

[0032] FIG. 3 schematically shows the configuration of an optical signal for channel setting. The optical signal S for channel setting includes at least local channel information L and remote channel information R held in the optical transceiver. The local channel information L is information indicating the channel of the optical signal S for channel setting transmitted by the optical transceiver when transmitting the optical signal S for channel setting in the channel setting process. The remote channel information R is information indicating the channel of the optical signal S for channel setting received when the optical transceiver receives the optical signal S for channel setting in the channel setting process. Note that the optical signal S for channel setting may include other information as necessary. FIG. 3 shows an example in which the optical signal S for channel setting includes header information OH.

[0033] In this embodiment, the optical signal for channel setting is transmitted by being superimposed on a main signal modulated based on a data signal to be transmitted and received, which is exchanged between two optical transceivers (for example, the above-described optical transceivers A2 and B2) that transmit and receive optical signals. The optical signal for channel setting can be transmitted by being superimposed on the main signal, for example, by using a modulation method such as amplitude-shift keying (ASK), phase-shift keying (PSK), or frequency-shift keying (FSK). Note that the modulation methods shown here are merely examples, and various modulation methods can be applied as long as the optical signal for channel setting can be superimposed on the main signal.

[0034] Here, the configuration of the optical transceiver according to this embodiment will be described. FIG. 4 schematically shows the basic configuration of the optical transceiver according to Embodiment 1. FIG. 5 shows the configuration of the optical transceiver according to Embodiment 1 in more detail. Here, since the optical transceivers A1 to A25 and B1 to B25 have the same configuration, the optical transceiver 100 having the same structure as these will be described as a representative.

[0035] The optical transceiver 100 includes a wavelength-variable optical transmission unit 10, a wavelength-variable optical reception unit 20, and a control unit 30. The control unit 30 controls the operations of the wavelength-variable optical transmission unit 10 and the wavelength-variable optical reception unit 20, for example, in response to a command signal INS given from an optical transmission device on which the optical transceiver 100 is mounted. The control unit 30 includes an arithmetic unit 31 and a storage unit 32.

[0036] The wavelength-variable optical transmission unit 10 is configured to be able to change the wavelength of the optical signal to be transmitted, that is, the channel. The wavelength-variable optical transmission unit 10 includes a drive unit 11 and an optical signal transmission unit 12. The drive unit 11 outputs a drive signal DRV to the optical signal transmission unit 12 based on the received main signal (data signal) IN. The wavelength-variable optical signal transmission unit 12 is configured, for example, as a TOSA (Transmitter Optical Sub-Assembly), and is configured to be able to output an optical signal LS1 modulated according to the drive signal DRV. As described above, the optical transceiver 100 can superimpose and output an optical signal for channel setting on the main signal. Therefore, the optical signal LS1 modulated according to the drive signal DRV is an optical signal composed of only the main signal MS1, or an optical signal in which the channel setting optical signal S1 is superimposed on the main signal MS1.

[0037] The wavelength-variable optical reception unit 20 is configured to be able to change the wavelength of the optical signal to be received, that is, the channel. The wavelength-variable optical reception unit 20 includes an amplification unit 21 and an optical signal reception unit 22. The wavelength-variable optical signal reception unit 22 is configured, for example, as a ROSA (Receiver Optical Sub-Assembly), converts the received optical signal LS2 into an output signal DAT which is an electrical signal, and outputs it to the amplification unit 21. The amplification unit 21 is configured, for example, as a limiting amplifier, amplifies the output signal DAT to a predetermined amplitude, and outputs the amplified output signal OUT to the outside of the optical transceiver 100, for example, to an optical transmission device on which the optical transceiver 100 is mounted. As described above, the optical transceiver 100 can receive an optical signal in which an optical signal for channel setting is superimposed on the main signal. Therefore, the optical signal LS2 is an optical signal composed of only the main signal MS2, or a signal in which the channel setting optical signal S2 is superimposed on the main signal MS2. When the main signal MS 2 with the channel setting optical signal S 2 superimposed is received, the amplification unit 21 separates and outputs the output signal OUT based on the main signal MS 2 and separates the detection signal DET based on the channel setting optical signal S2 and outputs it to the arithmetic unit 31 of the control unit 30.

[0038] Next, the transmission of the optical signal for channel setting in the optical transceiver 100 will be described. FIG. 6 shows the transmission of the optical signal for channel setting in the optical transceiver 100. Note that in FIG. 6, in order to focus on the optical signal S1 for channel setting, the display of the main signal MS1 is omitted. The arithmetic unit 31 of the control unit 30 can superimpose a signal for channel setting on the drive signal DRV output by the drive unit 11 by giving a control signal CON to the drive unit 11. At this time, by loading the local channel information L and the remote channel information R on the control signal CON, the optical signal S1 for channel setting superimposed on the main signal MS1 output by the optical signal transmission unit 12 will include the local channel information L and the remote channel information R. The arithmetic unit 31 S1 can appropriately read the local channel information L and the remote channel information R to be loaded on the signal S1 for channel setting from the storage unit 32. FIG. 6 shows an example of the optical signal S1 for channel setting, and it goes without saying that it can be appropriately modulated according to the modulation method for superimposing on the main signal MS1. , chi

[0039] Next, the reception of the optical signal for channel setting in the optical transceiver 100 will be described. FIG. 7 shows the reception of the optical signal for channel setting in the optical transceiver 100. Note that in FIG. 7, in order to focus on the optical signal S2 for channel setting, the display of the main signal MS2 is omitted. When the optical signal receiving unit 22 receives an optical signal with the optical signal S2 for channel setting superimposed thereon, the amplifying unit 21 outputs a detection signal DET based on the optical signal S2 for channel setting to the arithmetic unit 31 of the control unit 30. Thereby, the control unit 30 can receive the local channel information L and the remote channel information R. The arithmetic unit 31 can appropriately write the received local channel information L and remote channel information R into the storage unit 32. FIG. 7 shows an example of the optical signal S2 for channel setting, and it goes without saying that it can be appropriately modulated according to the modulation method for superimposing on the main signal MS2. S2

[0040] Next, the channel setting process of the optical transceiver using the above-described optical signal for channel setting will be described. The optical transceiver A2 and the optical transceiver B2 determine the channels used for transmitting and receiving optical signals between each other in the following procedure by changing the local channel information L, that is, by transmitting the optical signal for channel setting while sweeping the local channel. FIG. 8 shows an example of the optical signal for channel setting transmitted and received between the optical transceiver A2 and the optical transceiver B2 in the channel setting process. FIG. 9 shows the state transition in the channel setting process.

[0041] At the time of starting the channel setting process, the optical transceivers A2 and B2 are in a state where the transmission channel and the reception channel to be set are unknown (hereinafter, state EU: Each channel Unknown). That is, neither the optical transceiver of the transmission partner nor the optical transceiver that transmits the optical signal to be received is specified.

[0042] Thereafter, the optical transceivers A2 and B2 repeatedly transmit the optical signal for channel setting while sweeping the local channel. Here, it is assumed that the local channel starts from channel CH1 and is swept in ascending order.

[0043] Hereinafter, the optical transceiver B2 is also referred to as the first optical transceiver, and the optical transceiver A2 is also referred to as the second optical transceiver. The optical signal for channel setting output by the optical transceiver B2 is also referred to as the first optical signal for channel setting. The optical signal for channel setting output by the optical transceiver A2 is also referred to as the second optical signal for channel setting.

[0044] Channel CH3 is also referred to as the first channel, and channel CH4 is also referred to as the second channel.

[0045] The local channel information LB of the optical transceiver B2 is also referred to as the first channel information, and the local channel information LA of the optical transceiver A2 is also referred to as the second channel information. The remote channel information RB of the optical transceiver B2 is the third channel information, and the remote channel information LA of the optical transceiver A2 is the4 Also referred to as the channel information of

[0046] (1) SA1 / LA: CH1, RA: NONE In the example of FIG. 8, the optical transceiver A2 first transmits an optical signal SA1 for channel setting of channel CH1, where the local channel information LA is channel CH1 and the remote channel information RA is empty (NONE). In this example, channel CH1 is the channel used for transmission from the optical transceiver A1 to the optical transceiver B1. That is, the receiving port of the optical transceiver B1 is connected to the port of channel CH1 of the optical multiplexer / demultiplexer M2 of the optical transmission device 2. Therefore, the optical signal SA1 for channel setting is blocked by the optical multiplexer / demultiplexer M2 and does not reach the optical transceiver B2.

[0047] (2) SB1 / LB: CH1, RB: NONE Next, the optical transceiver B2 transmits an optical signal SB1 for channel setting of channel CH1, where the local channel information LB is channel CH1 and the remote channel information RB is empty (NONE). Since the transmitting port of the optical transceiver A1 is connected to the port of channel CH1 of the optical multiplexer / demultiplexer M1 of the optical transmission device 1, the optical signal SB1 for channel setting is blocked by the optical multiplexer / demultiplexer M1 and does not reach the optical transceiver A2.

[0048] (3) SA2 / LA: CH2, RA: NONE Next, the optical transceiver A2 transmits an optical signal SA2 for channel setting of channel CH2, where the local channel information LA is channel CH2 and the remote channel information RA is empty (NONE). In this example, channel CH2 is the channel used for transmission from the optical transceiver B1 to the optical transceiver A1. That is, the transmitting port of the optical transceiver B1 is connected to the port of channel CH2 of the optical multiplexer / demultiplexer M2 of the optical transmission device 2. Therefore, the optical signal SA2 for channel setting is blocked by the optical multiplexer / demultiplexer M2 and does not reach the optical transceiver B2.

[0049] (4) SB2 / LA: CH2, RA: NONE Next, the optical transceiver B2 transmits an optical signal SB2 for channel setting of channel CH2, where the local channel information LB is channel CH2 and the remote channel information RB is empty (NONE). Since the receiving port of the optical transceiver A1 is connected to the port of channel CH2 of the optical multiplexer / demultiplexer M1 of the optical transmission device 1, the optical signal SB2 for channel setting is blocked by the optical multiplexer / demultiplexer M1 and does not reach the optical transceiver A2.

[0050] (5) SA3 / LA: CH3, RA: NONE, State transition: EU → PK Next, the optical transceiver A2 transmits an optical signal SA3 for channel setting of channel CH3, where the local channel information L is channel CH3 and the remote channel information R is empty (NONE). In this example, channel CH3 is the channel used for transmission from the optical transceiver A2 to the optical transceiver B2. That is, the receiving port of the optical transceiver B2 is connected to the port of channel CH3 of the optical multiplexer / demultiplexer M2 of the optical transmission device 2. Therefore, the optical signal SA3 for channel setting of channel CH3 is received by the optical transceiver B2 via the optical multiplexer / demultiplexer M2.

[0051] As a result, the optical transceiver B2 can receive channel CH3 as the local channel information LA of the optical transceiver A2. Since the local channel information LA of the optical transceiver A2 is the remote channel information RB for the optical transceiver B2, the optical transceiver B2 fixes the remote channel information RB to channel CH3.

[0052] At this time, the optical transceiver B2 is in a state where it has detected the transmission channel of the other optical transceiver A2 (state PK: Partner CH Known), and the state transitions from EU to PK.

[0053] (6) SB4 / LB: CH3, RB: NONE Next, optical transceiver B2 transmits an optical signal SB3 for channel setting of channel CH3, where the local channel information LB is channel CH3 and the remote channel information RB is channel CH3. Since the transmission port of optical transceiver A2 is connected to the port of channel CH3 of optical multiplexer / demultiplexer M1 of optical transmission device 1, the optical signal SB3 for channel setting of channel CH3 is blocked by optical multiplexer / demultiplexer M1 and does not reach optical transceiver A2.

[0054] (7)SA4 / LA:CH4,RA:NONE Next, optical transceiver A2 transmits an optical signal SA4 for channel setting of channel CH4, where the local channel information LA is channel CH4 and the remote channel information RA is empty (NONE). In this example, channel CH4 is the channel used for transmission from optical transceiver B2 to optical transceiver A2. That is, the transmission port of optical transceiver B2 is connected to the port of channel CH4 of optical multiplexer / demultiplexer M2 of optical transmission device 2. Therefore, the optical signal SA4 for channel setting of channel CH4 is blocked by optical multiplexer / demultiplexer M2 and does not reach optical transceiver B2.

[0055] (8)SB4 / LB:CH4,RA:CH3, State transition: EU→EK Next, optical transceiver B2 transmits an optical signal SB4 for channel setting of channel CH4, where the local channel information LB is channel CH4 and the remote channel information RB is channel CH3. The reception port of optical transceiver B2 is connected to the port of channel CH4 of optical multiplexer / demultiplexer M1 of optical transmission device 1. Therefore, the optical signal SB4 for channel setting of channel CH4 is received by optical transceiver A2 via optical multiplexer / demultiplexer M1.

[0056] As a result, optical transceiver A2 can receive channel CH4 as the local channel information LB of optical transceiver B2. Since the local channel information LB of optical transceiver B2 is the remote channel information RA for optical transceiver A2, optical transceiver A2 fixes the remote channel information RA to channel CH4.

[0057] In addition, the optical transceiver A2 can receive channel CH3 as the remote channel information RB of the optical transceiver B2. Since the remote channel information RB of the optical transceiver B2 is local channel information LA for the optical transceiver A2, the optical transceiver A2 fixes the local channel information LA to channel CH3. Note that by fixing the local channel information LA to channel CH3, the transmission channel of the optical transceiver A2 is set, so the optical transceiver A2 stops channel sweeping.

[0058] At this time, the optical transceiver A2 is in a state (state EK: Each CH Known) where it has detected the transmission channel of the other optical transceiver B2 and the channels that can be transmitted from the optical transceiver A2 to the optical transceiver B2, and the state transitions from EU to EK.

[0059] (9) SA0 / LA: CH3, RA: CH4, State transition: PK → EK Next, the optical transceiver A2 transmits an optical signal SA0 for channel setting of channel CH3 in which the local channel information LA is fixed to channel CH3 and the remote channel information RA is fixed to channel CH4. The optical signal SA0 for channel setting of channel CH3 is received by the optical transceiver B2.

[0060] In this case, the optical transceiver B2 can receive channel CH4 as the remote channel information RA of the optical transceiver A2. Since the remote channel information RA of the optical transceiver A2 is local channel information LB for the optical transceiver B2, the optical transceiver B2 fixes the local channel information LB to channel CH4. Note that by fixing the local channel information LB to channel CH4, the transmission channel of the optical transceiver B2 is set, so the optical transceiver B2 stops channel sweeping.

[0061] At this time, the optical transceiver B2 enters a state (state EK) in which it has detected the transmission channel of the other optical transceiver A2 and the channel through which it can transmit from the optical transceiver B2 to the optical transceiver A2, and the state transitions from PK to EK.

[0062] (10) SB0 / LB:CH4, RB:CH3, State transition: EK→LE Next, the optical transceiver B2 transmits an optical signal SB0 for channel setting of channel CH4, in which the local channel information LB is fixed to channel CH4 and the remote channel information RB is fixed to channel CH3. The optical signal SB0 for channel setting of channel CH4 is received by the optical transceiver A2.

[0063] In this case, it can be confirmed that the local channel information LA of the optical transceiver A2 and the remote channel information RB of the optical transceiver B2 match on channel CH3, and the local channel information LB of the optical transceiver B2 and the remote channel information RA of the optical transceiver A2 match on channel CH4. Therefore, in this case, it can be confirmed that the channels used for transmission and the channels used for reception have been determined for the optical transceivers A2 and B2. Therefore, since no further channel setting process is required, the optical transceivers A2 and B2 end the channel setting process assuming that they are in a state where the connection is established (state LE: Link Established).

[0064] As a result, after the completion of the channel setting process, the optical transceivers A2 and B2 can transmit and receive optical signals using channels CH3 and CH4.

[0065] As described above, according to this configuration, the optical transceiver can autonomously set the channel for the optical signal to be transmitted and the channel for the optical signal to be received by referring to the information included in the received channel setting signal.

[0066] As a result, even when using a large number of channels as in the above-described optical communication system, for example, the time required for channel setting of the optical transceiver can be shortened.

[0067] In the manual channel setting operation, it is conceivable that the operation time for setting one channel requires an operation time of about one minute, for example, about 10 minutes. On the other hand, according to this configuration, although there are variations depending on the configuration of the optical communication system, automatic setting of one channel is possible with a setting time in seconds, for example, possible with a setting time of about several seconds. Thus, it can be understood that according to this configuration, the time required for channel setting of the optical transceiver can be significantly shortened.

[0068] In addition, by having the optical transceiver autonomously perform the channel setting, not only can the work by the operator be reduced, but also the operator can perform other work while the channel setting process is being performed, which is also advantageous in achieving labor saving in work.

[0069] Furthermore, since the optical transceiver can autonomously perform the channel setting, it is possible to prevent mistakes such as setting incorrect channels, which may occur in the manual channel setting operation, and it is also possible to improve the reliability of the channel setting.

[0070] Note that it is conceivable to start operation by mounting a number of optical transceivers less than the maximum number of mounts on the optical transmission device and then add optical transceivers later. In this case, in order to perform manual channel setting, complicated operations such as investigating the channels already in use and setting channels other than the ones already in use are required. On the other hand, according to the optical transceiver according to this embodiment, even if the channels already in use are not known, channel setting can be performed autonomously, which is also advantageous in terms of shortening the operation time and achieving labor saving when adding optical transceivers.

[0071] In the above description, the optical transceivers A2 and B2 have been described. Needless to say, the other optical transceivers A1, A3 to A25, B1, B3 to B25 can also execute the channel setting process in the same manner.

[0072] In the above description, the case where the optical transceiver changes the channel of the optical signal for channel setting in ascending order from channel CH1 has been described, but this is merely an example. For example, the optical transceiver may change the channel of the optical signal for channel setting in descending order. Also, for example, the optical transceiver may change the channel of the optical signal for channel setting in any order other than descending and ascending orders.

[0073] Embodiment 2 In Embodiment 1, the optical transceiver that autonomously performs channel setting has been described. However, when the channel used by the optical transceiver is known in advance, the work may be made more efficient by manually performing the channel setting. The optical transceiver according to Embodiment 1 sweeps channels when performing channel setting, but it is conceivable that the number of channels to be swept until reaching the channel to be set increases. In this case, it takes a long time until the channel setting is completed. On the other hand, when the channel used by the optical transceiver is known, even after the autonomous channel setting has started, the channel sweep can be omitted by manually performing the channel setting. Thereby, the time required for channel setting can be reduced, and an improvement in the efficiency of the channel setting work can be expected.

[0074] Therefore, in this embodiment, an optical transceiver capable of not only autonomous channel setting but also manual channel setting will be described. FIG. 10 schematically shows the configuration of the optical transceiver 200 according to Embodiment 2. The optical transceiver 200 has a configuration in which the control unit 30 of the optical transceiver 100 is replaced with a control unit 40. The arithmetic unit 41 and the storage unit 42 of the control unit 40 respectively correspond to the arithmetic unit 31 and the storage unit 32 of the control unit 30. In addition to the same operations as the control unit 30, the control unit 40 is configured to be able to perform channel setting according to a command signal INS_M for instructing manual channel setting given by a user of a device such as the optical transceiver 200 or a host device connected to the optical transceiver 200.

[0075] Subsequently, the manual channel setting process in this embodiment will be described. Here, similar to FIG. 2, it is assumed that optical transceivers A1 to A25 having the same configuration as the optical transceiver 200 are provided in the optical transmission device 1, and optical transceivers B1 to B25 having the same configuration as the optical transceiver 200 are provided in the optical transmission device 2.

[0076] Similar to Embodiment 1, when the optical transceiver A2 and the optical transceiver B2 receive the command signal INS, they start autonomous channel setting by changing the local channel information L, that is, by transmitting an optical signal for channel setting while sweeping the local channel. However, in this embodiment, it is assumed that channel CH3 is assigned as the transmission channel of the optical transceiver A2 and channel CH4 is assigned as the transmission channel of the optical transceiver B2 in advance. Therefore, in order to perform manual channel setting after the start of autonomous channel setting, the user gives a command signal INS_M for specifying the channel used for transmission and reception to the optical transceiver A2.

[0077] Hereinafter, the channel setting operation will be described in order. FIG. 11 shows an example of an optical signal for channel setting transmitted and received between the optical transceiver A2 and the optical transceiver B2 in the channel setting process according to the second embodiment. Here, an example will be described in which after the optical transceiver A2 and the optical transceiver B2 each transmit a channel setting signal once, a command signal INS_M is given to the optical transceiver A2 to perform manual channel setting. (1) SA1 / LA:CH1, RA:NONE In the example of FIG. 11, similar to the example of FIG. 8, the optical transceiver A2 first transmits an optical signal SA1 for channel setting of channel CH1 in which the local channel information LA is channel CH1 and the remote channel information RA is empty (NONE). In this example, channel CH1 is a channel used for transmission from the optical transceiver A1 to the optical transceiver B1. That is, the reception port of the optical transceiver B1 is connected to the port of channel CH1 of the optical multiplexer / demultiplexer M2 of the optical transmission device 2. Therefore, the optical signal SA1 for channel setting is blocked by the optical multiplexer / demultiplexer M2 and does not reach the optical transceiver B2.

[0078] (2) SB1 / LB:CH1, RB:NONE Next, similar to the example of FIG. 8, the optical transceiver B2 transmits an optical signal SB1 for channel setting of channel CH1 in which the local channel information LB is channel CH1 and the remote channel information RB is empty (NONE). Since the transmission port of the optical transceiver A1 is connected to the port of channel CH1 of the optical multiplexer / demultiplexer M1 of the optical transmission device 1, the optical signal SB1 for channel setting is blocked by the optical multiplexer / demultiplexer M1 and does not reach the optical transceiver A2. (3) INS_M input Here, in order to assign channel CH3 as the transmission channel of the optical transceiver A2 and assign channel CH4 as the transmission channel of the optical transceiver B2, a command signal INS_M is given from the user to the optical transceiver A2. When the optical transceiver A2 receives the command signal INS_M, it stops autonomous channel setting, that is, channel sweeping. (4) SA0 / LA: CH3, RA: CH4, State Transition: EU → EK In response to the command signal INS_M, the optical transceiver A2 transmits the optical signal SA0 for channel setting of channel CH3, in which the local channel information LA is fixed to channel CH3 and the remote channel information RA is fixed to channel CH4. The optical signal SA0 for channel setting of channel CH3 is received by the optical transceiver B2. At this time, since the state in which the channel used by the optical transceiver A2 for transmission and reception is detected, the state of the optical transceiver A2 transitions from EU to EK.

[0079] Similar to the case of FIG. 8, the optical transceiver B2 receives channel CH3 as the local channel information LA of the optical transceiver A2 and channel CH4 as the remote channel information RA. The local channel information LA and the remote channel information RA of the optical transceiver A2 are the remote channel information RB and the local channel information LB for the optical transceiver B2, respectively. Therefore, the optical transceiver B2 fixes the local channel information LB to channel CH4 and the remote channel information RB to channel CH3. Note that by fixing the local channel information LB and the remote channel information RB, the transmission channel of the optical transceiver B2 is set, so the optical transceiver B2 stops the channel sweep. As a result, the optical transceiver B2 enters a state (state EK) in which it has detected the transmission channel of the counterpart optical transceiver A2 and the channel through which the optical transceiver B2 can transmit to the optical transceiver A2, so the state transitions from EU to EK.

[0080] (5) SB0 / LB: CH4, RB: CH3, State Transition: EK → LE The optical transceiver B2 transmits the optical signal SB0 for channel setting of channel CH4, in which the local channel information LB is fixed to channel CH4 and the remote channel information RB is fixed to channel CH3. The optical signal SB0 for channel setting of channel CH4 is received by the optical transceiver A2.

[0081] Similar to the case of FIG. 8, it can be confirmed that for optical transceivers A2 and B2, the local channel information LA of optical transceiver A2 and the remote channel information RB of optical transceiver B2 match on channel CH3, and the local channel information LB of optical transceiver B2 and the remote channel information RA of optical transceiver A2 match on channel CH4. Therefore, assuming that the channels used for transmission and reception are determined, optical transceivers A2 and B2 transition to a state where the connection is established (state LE: Link Established) and end the channel setting process.

[0082] As a result, after the manual channel setting is completed, similar to Embodiment 1, optical transceivers A2 and B2 can transmit and receive optical signals using channels CH3 and CH4.

[0083] As described above, according to this configuration, even after the optical transceiver starts autonomous channel setting, it can stop the autonomous channel setting by receiving the command signal INS_M and set the transmission channel and reception channel specified by the command signal INS_M. Also, the optical transceiver that is the communication partner of the optical transceiver that has received the command signal can set the transmission channel and reception channel by receiving the optical signal for channel setting from the optical transceiver that has received the command signal INS_M.

[0084] When viewed from the user of the system in which the optical transceiver is implemented, the channel settings of the two optical transceivers can be easily performed manually by simply giving a command signal for specifying the channels used for transmission and reception to one of the two optical transceivers that transmit and receive optical signals.

[0085] As a result, without requiring channel scanning in autonomous channel setting, by performing interrupt processing on the command signal INS_M in software, the channel setting operation can be preferentially and quickly completed. In the example of FIG. 11, compared with the example of FIG. 8, it can be understood that the transmission and reception of the optical signals SA2 to SA4 and SB2 to SB4 for channel setting associated with channel scanning can be reduced, and the time required for channel setting can be shortened by the time required for the transmission and reception of the reduced optical signals for channel setting.

[0086] In the above description, the optical transceivers A2 and B2 have been described with attention. Needless to say, the same manual channel setting process can also be executed for the other optical transceivers A1, A3 to A25, B1, and B3 to B25.

[0087] In addition, in the above description, an example has been described in which a command signal is given when both of the two optical transceivers that transmit and receive optical signals are in the state EU where the transmission channel and the reception channel to be set are unknown, and the channel setting is performed manually. However, this is merely an example. That is, as shown in FIG. 8, after starting the autonomous channel setting, each of the two optical transceivers that transmit and receive optical signals may be in the state PK in which the transmission channel of the other optical transceiver is detected, or in the state EK in which the transmission channel of the other optical transceiver and the channel that can be transmitted to the other optical transceiver are detected but the channel setting has not been established. Even in this case, by giving a command signal to one of the two optical transceivers that transmit and receive optical signals, the autonomous channel setting being performed by the optical transceiver that has received the command signal can be stopped, and the channel used for transmission and reception can be set manually. Also, the optical transceiver that is the communication partner of the optical transceiver that has received the command signal can also set the channel used for transmission and reception manually by receiving the optical signal for channel setting from the optical transceiver that has received the command signal (that is, the optical signal SA0 or SB0 for channel setting in FIGS. 8 and 11).

[0088] Embodiment 3 In Embodiments 1 and 2, the channel settings of two optical transceivers for transmitting and receiving optical signals were described. However, as the signal superimposed on the main signal, which is the data signal to be transmitted and received, not only the above-described channel setting signal but also a control signal for the optical transceiver of the communication partner and the host device to which the optical transceiver of the communication partner is connected can be superimposed. In this embodiment, an optical transceiver capable of superimposing a control signal on the main signal will be described.

[0089] FIG. 12 schematically shows the configuration of an optical transceiver 300 according to Embodiment 3. The optical transceiver 300 according to this embodiment has a configuration in which the control unit 30 of the optical transceiver 100 is replaced with a control unit 50. The arithmetic unit 51 and the storage unit 52 of the control unit 50 respectively correspond to the arithmetic unit 31 and the storage unit 32 of the control unit 30.

[0090] The optical transceiver 300 superimposes a control signal CON1 for controlling the operation of the optical transceiver of the communication partner or the host device to which the optical transceiver of the communication partner is connected on the main signal MS1, and outputs it as an optical signal LS1. Further, the optical transceiver 300 receives an optical signal LS2 in which a control signal CON2 output from the optical transceiver of the communication partner is superimposed on the main signal MS2, and is configured to be operable according to the control signal CON2 . Note that since the transmission and reception of the control signal are the same as those of the channel setting optical signal, the description thereof is omitted.

[0091] Subsequently, the transmission of the control signal and the corresponding operation in this embodiment will be described. FIG. 13 schematically shows the configuration of an optical communication system according to Embodiment 3 and an example of transmission and reception of optical signals. Similar to Embodiment 1 and Embodiment 2, optical transceivers A1 to A25 having the same configuration as the optical transceiver 300 are provided in the optical transmission device 1, and optical transceivers B1 to B25 having the same configuration as the optical transceiver 300 are provided in the optical transmission device 2.

[0092] The optical transceivers A1 to A25 installed in the optical transmission device 1 are connected to a host device 3 that communicates with the other party through the optical transceivers A1 to A25 and performs various processes necessary for communication. Between the optical transceivers A1 to A25 and the host device 3, they are respectively connected by data communication lines DA1 to DA25 that exchange data signals modulated onto the main signal by each transceiver and data signals obtained by demodulating the received main signal, and are respectively connected by communication lines CA1 to CA25 that exchange electrical signals other than the data signals.

[0093] The optical transceivers B1 to B25 installed in the optical transmission device 2 are connected to a host device 4 that communicates with the other party through the optical transceivers B1 to B25 and performs various processes necessary for communication. Between the optical transceivers B1 to B25 and the host device 4, they may be respectively connected by data communication lines DB1 to DB25 that exchange data signals modulated onto the main signal by each transceiver and data signals obtained by demodulating the received main signal, and are respectively connected by communication lines CB1 to CB25 that exchange electrical signals other than the data signals.

[0094] For the sake of simplicity of explanation, an example will be described in which a control signal CS superimposed on the main signal is transmitted from the optical transceiver A2 to the optical transceiver B2.

[0095] First, the case of controlling the optical transceiver of the communication partner will be described. FIG. 14 schematically shows the signal flow in the case of controlling the optical transceiver of the communication partner in the third embodiment. The transmitting optical transceiver A2 can instruct the receiving optical transceiver B2 to turn on / off the optical output, that is, to stop and start the transmission of the optical signal, by superimposing the control signal CS on the main signal MS_A2 and transmitting it. Note that the optical transceiver can output a control signal in response to the application of signals such as the above-described command signal INS and command signal INS_M.

[0096] Also, by superimposing the control signal CS on the main signal MS_A2 and transmitting it, the optical transceiver A2 can request information such as the set parameters of the communication partner's optical transceiver B2. The optical transceiver B2 that has received the request superimposes the response signal RES indicating the held information on the main signal MS_B2 and transmits it to the optical transceiver A2. The optical transceiver A2 receives the response signal RES, converts it into the response signal RES_E which is an electrical signal, and transfers it to the optical transmission device 1 and other devices as necessary. The information to be requested is, for example, set information such as the transmission channel, reception channel, optical output, optical input level, transceiver temperature, laser state monitoring (wavelength monitor, laser temperature, laser current value), optical transceiver product name, and version of the program body.

[0097] Next, the case of controlling the host device of the communication partner will be described. FIG. 15 schematically shows the signal flow when controlling the host device to which the optical transceiver of the communication partner is connected in the third embodiment. The optical transceiver A2 can also instruct the on / off of the communication process of the host device 4 to which the communication partner's optical transceiver B2 is connected by transmitting the control signal CS. In this case, the control signal CS is transmitted from the optical transceiver A2 to the optical transceiver B2. The optical transceiver B2 receives the control signal CS, converts it into the control signal CS_E which is an electrical signal, and transfers it to the optical transmission device 2 through the communication line CB2. The host device 4 can stop and start the communication process according to the control signal CS_E.

[0098] In addition, the optical transceiver A2 can also request information held by the host device 4 to which the communication partner's optical transceiver B2 is connected by transmitting a control signal CS. In this case, the host device 4 outputs a response signal RES_E, which is an electrical signal indicating the information requested by the control signal CS_E, to the optical transceiver B2 through the communication line CB2. The optical transceiver B2 superimposes the response signal RES_E as an optical signal RES on the main signal MS_B2 and transmits it to the optical transceiver A2. The optical transceiver A2 receives the response signal RES, converts it into an electrical response signal RES_E, and transfers it to the host device 3 or other devices through the communication line CA2 as necessary. The information to be requested is, for example, setting information such as the number of connected optical transceivers and the transmission / reception channels of each optical transceiver.

[0099] As described above, according to this configuration, by superimposing a control signal on the main signal and transmitting it from one of the two optical transceivers that transmit and receive optical signals to the other optical transceiver of the communication partner, it is possible to control the operations of the optical transceiver of the communication partner and the host device to which the optical transceiver of the communication partner is connected.

[0100] The optical communication system shown in FIG. 13 described in this embodiment is used, for example, in a fifth-generation mobile communication system (hereinafter referred to as 5G). In such a system, it is known that base stations equipped with optical transmission devices are often installed in places where it is relatively difficult to access, such as in mountains, on the rooftops of buildings, and areas where lines are laid. In this case, it is difficult for workers to reach the base station itself in the first place, and workers with special skills are required. On the other hand, according to this configuration, since the operation can be remotely controlled by transmitting a control signal from an optical transceiver in a remote base station to the target optical transceiver, it is possible to cause the target optical transceiver or optical transmission device to perform the desired operation without dispatching workers to the base station. Therefore, the personnel, costs, and time required for maintenance and inspection work of optical transceivers and optical transmission devices can be significantly reduced.

[0101] Also, in 5G, it is known that, compared with previous mobile communication systems, since the frequency used for communication is short, the number of base stations to be installed becomes relatively large. Therefore, by performing remote control as in this configuration, even if many base stations are installed, the optical transmission device and the optical transceiver in the base station can be made to perform desired operations. Thereby, it is possible to effectively suppress an increase in the number of personnel, cost, and time for maintenance and inspection work due to an increase in the number of base stations.

[0102] Other Embodiments Note that the present invention is not limited to the above-described embodiments, and can be appropriately modified without departing from the gist. For example, the optical transmission device may be connected not only to the network shown in FIG. 1 but also to various networks including a trunk path and a branch path.

[0103] The number of optical transceivers and the number of channels provided in the optical transmission device are merely examples, and any number of optical transceivers and any number of channels may be provided.

[0104] In the above-described embodiments, it has been described that wavelength-division multiplexed signals are transmitted between optical transmission devices. Needless to say, the optical signals to be transmitted can be applied with various multiplexing methods other than wavelength division multiplexing, and various modulation methods can also be applied.

[0105] The configuration of the above-described optical transceiver is a simplified one for explaining the optical transceiver according to the above-described embodiments. Needless to say, various components such as a CDR (Clock Data Recovery) unit may be included.

[0106] In the above, an example in which an optical signal subjected to on / off modulation is used as an optical signal for channel setting has been described. However, an optical signal subjected to phase shift modulation other than on / off modulation may be used as an optical signal for channel setting.

[0107] In the above-described embodiments, the present invention has been mainly described in terms of the hardware configuration. However, the present invention is not limited thereto, and it is also possible to realize the control of the wavelength-variable optical transmitter and the wavelength-variable optical receiver by the control unit and the channel setting process by causing a CPU (Central Processing Unit) to execute a computer program. In this case, the arithmetic unit included in the control unit may be configured as a CPU. The program includes instructions (or software codes) that cause a computer to execute one or more functions described in the above-described embodiments when the program is loaded into the computer. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. Although not limited thereto, examples of non-transitory computer-readable media or tangible storage media include RAM (Random-access memory), ROM (Read-only memory), flash memory, SSD (Solid-state drive), or other types of storage technologies, such as CD (Compact disc)-ROM, DVD (Digital versatile disc), Blu-ray disc, or other types of optical disc storage devices, magnetic cassette, magnetic tape, magnetic disk storage, or other magnetic storage devices. The program may be transmitted by a transitory computer-readable medium or a communication medium. Although not limited thereto, examples of transitory computer-readable media or tangible storage media may include electrical, optical, acoustic, or other forms of propagated signals.

[0108] The storage unit included in the control unit can use various storage devices capable of writing and reading information, such as RAM, flash memory, SSD, optical disc storage devices, magnetic cassette, magnetic tape, and magnetic disk storage devices.

[0109] The present invention has been described with reference to the embodiments, but the present invention is not limited thereto. Various modifications that can be understood by those skilled in the art within the scope of the invention can be made to the configuration and details of the present invention.

Explanation of Signs

[0110] 1, 2 Optical transmission device 3, 4 Host device 10 Wavelength-variable optical transmitter 11 Driving unit 12 Optical signal transmitter 20 Wavelength-variable optical receiver 21 Amplifying unit 22 Optical signal receiver 30, 40, 50 Control unit 31, 41, 51 Arithmetic unit 32, 42, 52 Storage unit 100, A1~A25, B1~B25 Optical transceiver 1000 Optical communication system AMP Optical amplifier BS1, BS2 Terminal station C1, C2 Optical cable CA1~CA25, CB1~CB25 Data communication line CS, CS_E Control signal CON Control signal DAT Output signal DET Detection signal DRV Drive signal DA1~DA25, DB1~DB25 Data communication line IN Main signal INS, INS_M Command signal L, LA, LB Local channel information LS1, LS2 Optical signal M1, M2 Optical multiplexer / demultiplexer MS, MS1, MS2, MS_A2, MS_B2 Main signal OH Header information OUT Output signal R, RA, RB Remote channel information RES, RES_E Response signal Optical signals for channel settings of S, S1, S2, SA, SA0 to SA4, SB, SB0 to SB4

Claims

1. A wavelength-variable optical transmitter configured to be able to transmit a first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal by superimposing it on a first main signal obtained by modulating transmission target data; A wavelength-variable optical receiver that transfers second channel information indicating a channel of the second channel setting optical signal, which is included in the second channel setting optical signal, when receiving the second channel setting optical signal superimposed on a second main signal obtained by modulating reception target data from another optical transceiver; A control unit that controls the wavelength-variable optical transmitter and the wavelength-variable optical receiver; and The control unit: When receiving a first command signal for commanding autonomous channel setting, until the wavelength-variable optical receiver receives the second channel setting optical signal, the wavelength-variable optical transmitter is repeatedly made to transmit the first channel setting optical signal while changing the transmission channel of the first channel setting optical signal. When the wavelength-variable optical receiver receives the second channel setting optical signal, the autonomous channel setting is started in which the channel indicated by the second channel information is set as the channel of the optical signal received by the wavelength-variable optical receiver; A first designated channel of the optical signal transmitted by the wavelength-variable optical transmitter and a second designated channel of the optical signal received by the wavelength-variable optical receiver are determined by a user, and when a second command signal for commanding the control unit with respect to the first designated channel and the second designated channel is given before the autonomous channel setting is completed, the autonomous channel setting is stopped, the channel of the optical signal transmitted by the wavelength-variable optical transmitter is set to the first designated channel, and the channel of the optical signal received by the wavelength-variable optical receiver is set to the second designated channel. An optical transceiver.

2. The wavelength-variable optical transmitter is capable of transmitting a control signal to another optical transceiver by superimposing it on the first main signal, and the control unit controls the operation of the other optical transceiver by causing the wavelength-variable optical transmitter to transmit the control signal. The optical transceiver according to Claim 1.

3. The control unit controls turning on and off the optical output of the other optical transceiver by the control signal. The optical transceiver according to Claim 2.

4. The control unit requests information held by the other optical transceiver by the control signal. The other optical transceiver superimposes and outputs a signal indicating the requested information on the second main signal. The optical transceiver according to claim 2 or 3.

5. The control unit controls the on / off of the device to which the other optical transceiver is connected by the control signal. The optical transceiver according to any one of claims 2 to 4.

6. The control unit requests information held by the device to which the other optical transceiver is connected by the control signal. The other optical transceiver transfers the received request to the device. The device outputs a signal indicating the requested information to the other optical transceiver in response to the transferred request. The other optical transceiver superimposes and outputs a signal based on the signal received from the device on the second main signal. The optical transceiver according to any one of claims 2 to 5.

7. Two opposing optical transmission devices, comprising: a plurality of optical transceivers; and a first optical multiplexer / demultiplexer that multiplexes and outputs optical signals output by the plurality of optical transceivers and demultiplexes received optical signals to the plurality of optical transceivers according to channels. An optical cable connecting the two opposing optical transmission devices. The first optical transceiver, which is an optical transceiver of one of the optical transmission devices, A wavelength-variable optical transmission unit configured to be able to transmit the first channel setting optical signal including first channel information indicating the channel of the first channel setting optical signal by superimposing it on a first main signal obtained by modulating transmission target data. A wavelength-variable optical reception unit that transfers second channel information indicating the channel of the second channel setting optical signal included in the second channel setting optical signal when receiving the second channel setting optical signal superimposed on the second main signal obtained by modulating reception target data from the second optical transceiver, which is an optical transceiver of the other optical transmission device. A control unit that controls the wavelength-variable optical transmission unit and the wavelength-variable optical reception unit. The control unit When receiving a first command signal for commanding autonomous channel setting, until the wavelength-variable optical receiver receives the optical signal for the second channel setting, the wavelength-variable optical transmitter is caused to repeatedly transmit the optical signal for the first channel setting while changing the transmission channel of the optical signal for the first channel setting. When the wavelength-variable optical receiver receives the optical signal for the second channel setting, the autonomous channel setting is started in which the channel indicated by the second channel information is set as the channel of the optical signal received by the wavelength-variable optical receiver. A first designated channel of the optical signal transmitted by the wavelength-variable optical transmitter and a second designated channel of the optical signal received by the wavelength-variable optical receiver are determined by a user, and when a second command signal for commanding the first designated channel and the second designated channel to the control unit is given before the autonomous channel setting is completed, the autonomous channel setting is stopped, the channel of the optical signal transmitted by the wavelength-variable optical transmitter is set to the first designated channel, and the channel of the optical signal received by the wavelength-variable optical receiver is set to the second designated channel. Optical communication system.

8. A plurality of optical transceivers; A first optical multiplexer / demultiplexer that multiplexes and outputs the optical signals output by the plurality of optical transceivers and demultiplexes the received optical signal to the plurality of optical transceivers according to channels. The optical transceiver includes: A wavelength-variable optical transmitter configured to be able to transmit the optical signal for the first channel setting including first channel information indicating the channel of the optical signal for the first channel setting by superimposing it on a first main signal obtained by modulating transmission target data; A wavelength-variable optical receiver that transfers second channel information indicating the channel of the optical signal for the second channel setting, which is included in the optical signal for the second channel setting, when receiving the optical signal for the second channel setting superimposed on a second main signal obtained by modulating reception target data from an optical transceiver of another optical transmission device connected via an optical cable; A control unit that controls the wavelength-variable optical transmitter and the wavelength-variable optical receiver. The control unit is When receiving a first command signal for instructing autonomous channel setting, until the wavelength-variable optical receiver receives the second channel setting optical signal, the wavelength-variable optical transmitter is caused to repeatedly transmit the first channel setting optical signal while changing the transmission channel of the first channel setting optical signal. When the wavelength-variable optical receiver receives the second channel setting optical signal, start the autonomous channel setting for setting the channel indicated by the second channel information as the channel of the optical signal received by the wavelength-variable optical receiver. The first designated channel of the optical signal transmitted by the wavelength-variable optical transmitter and the second designated channel of the optical signal received by the wavelength-variable optical receiver are determined by the user. And when a second command signal for instructing the control unit to set the first designated channel and the second designated channel is given before the autonomous channel setting is completed, stop the autonomous channel setting, set the channel of the optical signal transmitted by the wavelength-variable optical transmitter to the first designated channel, and set the channel of the optical signal received by the wavelength-variable optical receiver to the second designated channel. Optical transmission device.

9. In an optical transceiver comprising a wavelength-variable optical transmitter configured to be able to transmit the first channel setting optical signal including first channel information indicating the channel of the first channel setting optical signal by superimposing it on a first main signal obtained by modulating transmission target data, and a wavelength-variable optical receiver configured to transfer second channel information indicating the channel of the second channel setting optical signal included in the second channel setting optical signal when receiving the second channel setting optical signal superimposed on a second main signal obtained by modulating reception target data from another optical transceiver, and a control unit for controlling the wavelength-variable optical transmitter and the wavelength-variable optical receiver. When receiving a first command signal for instructing autonomous channel setting, until the wavelength-variable optical receiver receives the second channel setting optical signal, the wavelength-variable optical transmitter is caused to repeatedly transmit the first channel setting optical signal while changing the transmission channel of the first channel setting optical signal. When the wavelength-variable optical receiver receives the second channel setting optical signal, start the autonomous channel setting for setting the channel indicated by the second channel information as the channel of the optical signal received by the wavelength-variable optical receiver. The first designated channel of the optical signal transmitted by the wavelength-variable optical transmitter and the second designated channel of the optical signal received by the wavelength-variable optical receiver are determined by the user. When a second command signal for commanding the first designated channel and the second designated channel is given before the autonomous channel setting is completed, the autonomous channel setting is stopped, the channel of the optical signal transmitted by the wavelength-variable optical transmitter is set to the first designated channel, and the channel of the optical signal received by the wavelength-variable optical receiver is set to the second designated channel. A method for setting an optical transceiver.

10. In an optical transceiver comprising: a wavelength-variable optical transmitter configured to be able to transmit a first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal by superimposing it on a first main signal obtained by modulating transmission target data; a wavelength-variable optical receiver configured to transfer second channel information indicating a channel of the second channel setting optical signal included in the second channel setting optical signal when receiving the second channel setting optical signal superimposed on a second main signal obtained by modulating reception target data from another optical transceiver; and a control unit having a computer that performs a process of controlling the wavelength-variable optical transmitter and the wavelength-variable optical receiver. When receiving a first command signal for commanding an autonomous channel setting, the wavelength-variable optical transmitter is repeatedly made to transmit the first channel setting optical signal while changing the transmission channel of the first channel setting optical signal until the wavelength-variable optical receiver receives the second channel setting optical signal. When the wavelength-variable optical receiver receives the second channel setting optical signal, a process of starting the autonomous channel setting for setting the channel indicated by the second channel information as the channel of the optical signal received by the wavelength-variable optical receiver is performed. The first designated channel of the optical signal transmitted by the wavelength-variable optical transmitter and the second designated channel of the optical signal received by the wavelength-variable optical receiver are determined by the user, and when a second command signal for commanding the first designated channel and the second designated channel is given before the autonomous channel setting is completed, the autonomous channel setting is stopped, the channel of the optical signal transmitted by the wavelength-variable optical transmitter is set to the first designated channel, and the channel of the optical signal received by the wavelength-variable optical receiver is set to the second designated channel, and causing the computer to perform the process. Program.

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